This invention relates to superconducting thin films obtained by laminating rare earth oxide thin films and having higher superconducting critical temperatures (Tc), and processes for producing the same.
It is reported in J. Phys. Soc. Japan, vol. 42(2), pp208-209 (1987) that superconductivity appears when a part of La in La.sub.2 CuO.sub.4, which is known as a conductive oxide having a layered perovskite structure, is replaced by Ba to make Tc over 30K. Possible high Tc superconductivity in the Ba--La--Cu--O system is discussed by J. G. Bednorz and K. A. Mulluer in Z. Phys. B-Condensed Matter 64, 189-193 (1986). But the materials disclosed therein are still low in Tc. Thus, materials having higher Tc are desired.